1. Field of the Invention
The present invention relates to a disc chucking apparatus having an improved claw structure to improve performance in centering and chucking a disc, a motor, and a disc driving device equipped with the motor.
2. Description of the Related Art
In general, a spindle motor disposed in a disc driving device rotates a disc to allow an optical pickup unit to read data recorded on the disc.
The disc is placed on and fixed to a disc chucking apparatus of the spindle motor and rotated with the rotation of the motor.
In this configuration, the inner circumferential surface of the disc is fitted over the outer circumferential surface of a centering base of the disc chucking apparatus, in which the center of the disc should be aligned with the center of the centering base in order to ensure the reliability of the disc in the recording or playback performance thereof.
The related art disc chucking apparatus has a plurality of chuck chips and claws to prevent a disc, fitted over the outer circumferential surface of the centering base, from being separated from the centering base while the motor operates.
The claws provide elasticity to the inner circumferential surface of the disc fixed to the centering base.
In the related art, the claws are fixed to the top of the centering base and provides electricity to the disc through protrusions protruding downwardly. However, in the structure of the claws according to the related art, the protrusions are pushed in the inner diameter direction of the disc when the disc is placed, such that the inner surface of the disc and the outer surfaces of the claws may not be in close contact.
Due to the structure of the claws in the related art, the elasticity of the claws is not transmitted horizontally to the disc, but rather to the upper portion of the disc. Therefore, the disc is likely to fluctuate while rotating, and this may become worse in the case of high density discs (e.g. Blu-ray discs).
Further, since the related art claws are not firmly in contact with the disc as described above, the centers of the disc and the centering base are not aligned when the motor operates, such that the performance of the disc in the recording or playback thereof is reduced.